Vehicle curtain airbag

ABSTRACT

A post-deployment, position-stabilized curtain airbag has a top edge from which an inflatable safety cushion is supported by a vehicle for deployment into a vehicle passenger compartment between occupant and occupant enclosure. A fill chamber is secured to the top edge of the safety cushion. An inflatable structural member is mechanically connected to the safety cushion. The fill chamber directs pressurized gas into the safety cushion and the structural member. The structural member deploys into the passenger compartment between the safety cushion and occupant enclosure limiting outboard displacement of the safety cushion. The structural member fully deploys after the safety cushion. Another structural member deploys along the top edge of the safety cushion limiting pivoting of the safety cushion there relative to the fill chamber. Pressurized gas enters each structural member through auxiliary passageways having oppositely directed entrances and outlets.

This application is a divisional of U.S. patent application Ser. No.12/573,442, filed Oct. 5, 2009, which is incorporated herein by thisreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to vehicle passenger safety modules thatuse pressurized gas from an inflator to deploy an airbag betweenpassengers and the occupant enclosure interior of a vehicle in the eventof a collision or rollover. More particularly, the present inventionpertains to curtain airbags that inflate at the sides of the passengercompartment between an occupant and the occupant enclosure of thevehicle.

2. Background

A typical airbag for a vehicle passenger safety module capturespressurized gas from an associated inflator, thereby becoming agas-filled cushion interposed between a vehicle occupant and theinterior vehicle surfaces of the occupant enclosure that surround thatoccupant. Typically, the inflator is ignited electrically in response toa momentum monitor carried in the vehicle.

The driver/passenger safety cushion of a curtain airbag deploysdownwardly from the ceiling trim at the side of the passengercompartment by filling with pressurizes gas from an associated inflator,typically assuming the form of a thin, elongated generally planarbarrier between occupants and the side windows of the vehicle.

A deployed curtain airbag safety cushion is accordingly stably securedat the top thereof to the occupant enclosure. The bottom of the safetycushion is by contrast relatively less restrained. Consequently, thesafety cushion below the top thereof may engage in undesirable outboardmotion that can expose an occupant to injury.

BRIEF SUMMARY OF THE INVENTION

According to teachings of the present invention, a post-deploymentposition-stabilized curtain airbag for installation in a vehicle toprotect an occupant in case of side impact or rollover includes aninflatable passenger safety cushion supportable at a top edge thereofinterior of the vehicle for deployment into the passenger compartment ofthe vehicle between the occupant and the occupant enclosure, a fillchamber secured to the top edge of the safety cushion in fluidcommunication therewith, and an inflatable structural membermechanically connected to the safety cushion. The fill chamber directspressurized gas from an inflator into the safety cushion to effect thedeployment thereof. The structural member is disposable uponinstallation in the vehicle for deployment into the passengercompartment between the deployed safety cushion and the occupantenclosure using pressurized gas directed through the fill chamber. Thedeployed structural member serves to limit outboard displacement of thedeployed safety cushion.

The full deployment of the structural member occurs subsequently to thefull deployment of the safety cushion. The safety cushion has a rearportion deploying toward the rear of the passenger compartment and aforward portion remote therefrom, and pressurized gas enters thestructural member through an auxiliary passageway communicating with therear portion of the safety cushion. Upon installation of the airbag inthe vehicle, the entrance to the auxiliary passageway from the rearportion of the safety cushion is oppositely directed from the outlet ofthe auxiliary passageway into the structural member. The structuralmember deploys along the top edge of the safety cushion, and thedeployed structural member serves to limit pivoting of the deployedsafety cushion at the top edge thereof relative to the fill chamber.

According to another more specific aspect of the present invention, acurtain airbag includes an inflatable passenger safety cushion asdescribed above having a rear portion deploying toward the rear of thepassenger compartment and a forward portion remote therefrom, a fillchamber secured to the top edge of the safety cushion in fluidcommunication therewith that directs pressurized gas from an inflatorinto the safety cushion to effect deployment thereof, and an inflatablestructural member mechanically connected to the rear portion of thesafety cushion. The structural member is disposable upon installation inthe vehicle for deployment into the passenger compartment between thedeployed safety cushion and the occupant enclosure using pressurized gasdirected from the fill chamber through the safety cushion. The deployedstructural member serves to limit outboard displacement of the rearportion of the deployed safety cushion. An auxiliary passagewaycommunicates between structural member and the lower edge, the rearedge, or the top edge of the rear portion of the safety cushion.Pressurized gas from the safety cushion enters the structural memberthrough the auxiliary passageway. Upon installation of the airbag in thevehicle, the entrance to the auxiliary passageway from the rear portionof the safety cushion is oppositely directed from the outlet of theauxiliary passageway into the structural member.

The safety cushion and the structural member are formed betweencoextensive flexible inboard and outboard panels. Upon installation ofthe airbag in the vehicle, the structural member is folded back upon thesafety cushion, and the fold between structural member and the safetycushion traverses an auxiliary passageway communicating between thesafety cushion and the structural member.

The full deployment of the structural member is completed after thecompletion of the full deployment of the safety cushion. For example, ifthe safety cushion fully deploys within about 50 milliseconds of sideimpact or rollover, the structural member fully deploys within about 150milliseconds of side impact or rollover.

According to yet another specific aspect of the present invention, acurtain airbag includes an inflatable passenger safety cushion and afill chamber as described above in combination with an inflatablestructural member mechanically connected to the safety cushion, thestructural member and disposable upon installation in the vehicle fordeployment into the passenger compartment along the top edge of thesafety cushion between the deployed safety cushion and the occupantenclosure. The structural member is mechanically connected to the safetycushion by the fill chamber. Pressurized gas directed through the fillchamber directly into the structural member inflates the structuralmember, which then serves to limit pivoting of the deployed safetycushion at the top edge thereof relative to the fill chamber. The lengthof the structural member may be made less than the length of the safetycushion. In such instances, the structural member deploys along aportion of the top edge of the safety cushion corresponding to theseated position of the occupant in the passenger compartment.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In order that the manner in which the above-recited and other featuresand advantages of the present invention are obtained will be readilyunderstood, a more particular description of the present inventionbriefly described above will be rendered by reference to specificembodiments thereof which are illustrated in the appended drawings.Understanding that these drawings depict only typical embodiments of thepresent invention and are not therefore to be considered to be limitingof scope thereof, the present invention will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 is an elevation view, of a first embodiment of an inflatedcurtain airbag embodying teachings of the present invention superimposedagainst profiles in phantom of the side windows and the exterior of atypical passenger vehicle;

FIG. 2 is an elevation view of the curtain airbag of FIG. 1 exclusively,illustrating functional divisions of the curtain airbag;

FIG. 3 is a cross section of the airbag of FIG. 2 taken along sectionline 3-3 therein superimposed against a profile in phantom of theoccupant enclosure and the exterior of the passenger vehicle of FIG. 1;

FIG. 4A is an elevation view of the curtain airbag of FIG. 2 in anunfolded condition with the inboard panel removed to depict on theoutboard panel shown the attachment zones at which the outboard and theinboard panels of the curtain airbag become mutually secured;

FIG. 4B is an elevation view similar to that of FIG. 4A depicting analternate second embodiment of a curtain airbag incorporating teachingsof the present invention;

FIG. 4C is an elevation view similar to that of FIGS. 4A and 4Bdepicting an alternate third embodiment of a curtain airbagincorporating teachings of the present invention;

FIG. 5 is an elevation view of the passenger safety cushion and the fillchamber of an inflated fourth embodiment of a curtain airbagincorporating teachings of the present invention with the vehicleoccupants of FIG. 1 in the foreground;

FIG. 6 is a cross section of the airbag of FIG. 5 taken along sectionline 6-6 therein superimposed against a profile in phantom of theoccupant enclosure and the exterior of the passenger vehicle of FIG. 1;and

FIG. 7 is an elevation view of the curtain airbag of FIG. 5 in anunfolded condition with the inboard panel removed to depict on theoutboard panel shown the attachment zones at which the outboard and theinboard panels of the curtain airbag become mutually secured.

DETAILED DESCRIPTION OF THE INVENTION

The presently preferred embodiments of the present invention will bebest understood by reference to the drawings, wherein like parts aredesignated by like numerals throughout. It will be readily understoodthat the components of the present invention, as generally described andillustrated in the figures herein, could be arranged and designed in awide variety of different configurations. Thus, the following moredetailed description of the embodiments of the present invention, asrepresented in FIGS. 1-7, is not intended to limit the scope of theinvention, as claimed, but is merely representative of presentlypreferred embodiments of the invention.

FIG. 1 is an elevation view of a first embodiment of a curtain airbag 10embodying teachings of the present invention. Airbag 10 has beendeployed downwardly into a passenger compartment 12 of a vehicle 14under the influence of pressurized gas entered into an open end 15 (seeFIG. 2) of airbag 10 from an associated inflator 16. Inflator 16 andairbag 10 are superimposed by way of perspective against profiles inphantom of a front side window 18, a rear side window 20, and theexterior 22 of vehicle 14.

In the foreground of airbag 10 are a front seat occupant 24 and a backseat occupant 26. Airbag 10 has inflated into a thin, planar barriersufficiently elongated to be interposed both between occupant 24 andfront side window 18, and between occupant 26 and rear side window 20.Occupants 24 and 26 are to be protected by airbag 10 in the case of aside impact or a rollover involving vehicle 14. Alternatively, adistinct but foreshortened curtain airbag, such as airbag 10, may bedisposed next to each of occupants 24 and 26 individually.

In the deployed condition, airbag 10 is stably secured at the top 28thereof to the occupant enclosure that surrounds vehicle compartment 12.The bottom 30 of airbag 10 is by contrast relatively less restrained,particularly in a lateral outboard-inboard direction. According toteachings of the present invention, the lateral positional stability ofairbag 10 after deployment is enhanced through the incorporation intoairbag 10 of a supplemental structural member that inflates with airbag10. By improving post-deployment lateral stability in airbag 10, theinflated structural member reduces the risk of injury to occupants 24and 26 because of outboard motion of airbag 10 below top 28.

FIG. 2 is a slightly enlarged elevation view of airbag 10 exclusively.Airbag 10 is fabricated from a pair of coextensive, congruent, flexible,gas-impermeable fabric panels. These include an inboard panel 32 visiblein FIG. 2, which comes to be disposed facing occupants 24 and 26 whenairbag 10 is deployed, and an outboard panel that is obscured in FIG. 2by inboard panel 32. The outboard panel of airbag 10 will, therefore, beintroduced in relation to a subsequent figure. The panels of airbag 10are disposed in alignment atop one another and secured with adhesiveand/or stitching at a continuous exterior attachment zone at the commonperiphery P of both. Enclosed thereby between the panels is an interiorspace in which airbag 10 captures pressurized gas and inflates. Suchpressurized gas G is shown diagrammatically in FIG. 2 as an arrow in theprocess of being delivered into airbag 10 through open end 15 thereof.Open end 15 of airbag 10 is the sole portion of common periphery P ofthe panels of airbag 10 that, being free of any exterior attachmentzone, are not secured to each other.

The fabric panels of airbag 10 are also secured to each other atselected interior attachment zones within periphery P. The interiorattachment zones of airbag 10 direct the flow of pressurized gas Gthroughout airbag 10 appropriately and determine the shape into whichairbag 10 will ultimately inflate. Of the various interior attachmentzones of airbag 10, only elongated plenum boundaries 34 a-34 f are shownin FIG. 2.

Plenum boundaries 34 a-34 f are positioned in an end-to-end alignmentthat mirrors the shape of top 28 of airbag 10. At the end of each ofplenum boundaries 34 a-34 f remote from open end 15 of airbag 10 is acorresponding gas flow gap 36 a-36 f. Thus, for example, gas flow gap 36a is located between plenum boundaries 34 a and 34 b, while gas flow gap36 f, the furthest gas flow gap from open end 15 of airbag 10, isbetween plenum boundary 34 f and periphery P of the panels of airbag 10.Pressurized gas G entering airbag 10 is initially directed away fromopen end 15, between plenum boundaries 34 a-34 f and top 28 of airbag10. Fractional portions Ga-Gf of pressurized gas G bleed through each ofgas flow gaps 36 a-36 f, respectively, entering and inflating theportion of airbag 10 between plenum boundaries 34 a-34 f and bottom 30of airbag 10. Thus, portion Ga of pressurized gas G enters the portionof airbag 10 between plenum boundaries 34 a-34 f and bottom 30 by way ofgas flow gap 36 a, while portion Gf enters through gas flow gap 36 f.

By way of functional overview, airbag 10 is thus divided by plenumboundaries 34 a-34 f into an elongated, tubular fill chamber 38 that islocated between plenum boundaries 34 a-34 f and top 28 of airbag 10, andan inflatable passenger safety cushion 40 that is located between plenumboundaries 34 a-34 f and bottom 30 of airbag 10. Safety cushion 40 has atop edge 42 identified in FIG. 2 by a dashed line just below plenumboundaries 34 a-34 f. Tubular fill chamber 38 is secured to top edge 42of safety cushion 40 and accordingly supports safety cushion 40 interiorof vehicle 14 for deployment into passenger compartment 12 in the mannerillustrated in FIG. 1. Tubular fill chamber 38 communicatespneumatically with safety cushion 40 at top edge 42 thereof by way ofgas flow gaps 36 a-36 f. Thus, fill chamber 38 directs pressurized gas Ginto safety cushion 40 in portions Ga-Gf, which vary in quantityrelative to each other according to the specific configuration of eachof gas flow gaps 36 a-36 f individually.

Safety cushion 40 has a rear portion 44 that deploys toward the rear ofpassenger compartment 12 and a forward portion 46 remote therefrom thatcorrespondingly deploys toward the front of passenger compartment 12.

FIG. 3 is a cross section of rear portion 44 of airbag 10 taken alongsection line 3-3 in FIG. 2. By way of perspective, that view of airbag10 is superimposed against profiles in phantom of exterior 22 of vehicle14 of FIG. 1 and of the occupant enclosure 48 for passenger compartment12. A rear view of back seat occupant 26 is also included.

Airbag 10 has deployed downwardly from the ceiling trim of vehicle 14into passenger compartment 12 between occupant 26 and the portion ofoccupant enclosure 48 at rear side window 20. Fill chamber 38 supportssafety cushion 40 from top edge 42 thereof and communicates thereintothrough gas flow gap 36 f. The panels of airbag 10, inboard panel 32 andoutboard panel 50 not previously visible in FIG. 2, are secured along anexterior attachment zone at their common periphery P, thereby enclosingthe interior space in which airbag 10 captures and inflates withpressurized gas G.

According to one aspect of the present invention, a curtain airbag, suchas airbag 10, includes an inflatable structural member 52 that ismechanically connected to rear portion 44 of safety cushion 40.Structural member 52 is disposable upon installation in vehicle 14 fordeployment into passenger compartment 12 between the deployed safetycushion 40 and occupant enclosure 48 using pressurized gas from fillchamber 38. As thusly deployed, structural member 52 serves to limitoutboard displacement of rear portion 44 of the deployed safety cushion40, reducing the risk of injury to occupant 26. Structural member 52 isfabricated from the same inboard panel 32 and outboard panel 50 as areused in forming fill chamber 38 and safety cushion 40 and in the samemanner, by securement along an exterior attachment zone at their commonperiphery P.

An auxiliary passageway 54, also fabricated from inboard panel 32 andoutboard panel 50, communicates between rear portion 44 of safetycushion 40 and structural member 52. Auxiliary passageway 54 has anentrance 56 at safety cushion 40 that receives pressurized gas directedinto safety cushion 40 from fill chamber 38 and an outlet 58 atstructural member 52 at which that pressurized air enters and inflatesstructural member 52.

When airbag 10 is installed in vehicle 14, structural member 52 in adeflated condition is folded back upon and optionally secured to safetycushion 40 in a deflated condition. As a result, a fold arises betweenstructural member 52 and safety cushion 40. This fold traversesauxiliary passageway 54, and entrance 56 to auxiliary passageway 54 isoriented in a direction opposite from the direction of outlet 58 ofauxiliary passageway 54. This tortuous gas flow pathway between safetycushion 40 and structural member 52 combines with the filling ofstructural member 52 indirectly from inflation chamber 38 by way of rearportion 44 of safety cushion 40, to insure that the full deployment ofstructural member 52 is completed after the completion of the fulldeployment of safety cushion 40. For example, where safety cushion 40fully deploys within about 50 milliseconds of a side impact or arollover involving vehicle 14, structural member 52 can be expected tofully deploy within about 150 milliseconds of that side impact orrollover. These inflation speeds meet current industry standards.

FIG. 4A is an elevation view of airbag 10 of FIGS. 2 and 3 in anunfolded condition with inboard panel 32 removed to depict on outboardpanel 50 the attachment zones at which the panels of airbag 10 becomemutually secured. These attachment zones include, not only plenumboundaries 34 a-34 f already introduced in FIG. 2, but an exteriorattachment zone 60 at periphery P and internal attachment ribs 62 thatsubdivide safety cushion 40 into cushion chambers 64 a-64 f. The portionGf of pressurized gas G entering cushion chamber 64 f at rear portion 44of safety cushion 40 is identified, as is the fraction G₅₂ of portion Gfthat eventually enters structural member 52 by way of auxiliarypassageway 54. A fold F₅₂ is also shown at the lower edge 66 of rearportion 44 of safety cushion 40. When airbag 10 is to be installed in avehicle, structural member 52 in a deflated condition is rotateddownward from the plane of FIG. 4A about fold F₅₂ until structuralmember 52 rests against rear portion 44 of safety cushion 40, which isalso then in a deflated condition. Auxiliary passageway 54 andstructural member 52 thus communicate with rear portion 44 of safetycushion 40 at lower edge 66 thereof.

FIG. 4B is an elevation view similar to that of FIG. 4A depicting analternate second embodiment of a curtain airbag 80 incorporatingteachings of the present invention. Airbag 80 includes a fill chamber 82and a safety cushion 84 with a rear portion 86 that deploys toward therear of passenger compartment 12 of vehicle 14 of FIG. 1. Safety cushion84 is subdivided into cushion chambers 88 a-88 f by the internalattachment zones between the panels of airbag 80, which are not labeledin FIG. 4B.

To enhance the post-deployment lateral stability of safety cushion 84,airbag 80 also includes an inflatable structural member 90. Structuralmember 90 communicates with rear portion 86 of safety cushion 84 at arear edge 92 thereof by way of an auxiliary passageway 94 that has anentrance 96 at cushion chamber 88 f and an outlet 98 at structuralmember 90. The portion Gf of pressurized gas G entering cushion chamber88 f at rear portion 86 of safety cushion 84 is identified, as is thefraction G₉₀ of portion Ga that eventually enters structural member 90by way of auxiliary passageway 94. A fold F₉₀ is also shown at rear edge92 of rear portion 86 of safety cushion 84. When airbag 80 is to beinstalled in a vehicle, structural member 90 in a deflated condition isrotated from the plane of FIG. 4B about fold F₉₀ until structural member90 rests against rear portion 86 of safety cushion 84, which is also ina deflated condition.

FIG. 4C is an elevation view similar to that of FIGS. 4A and 4Bdepicting an alternate third embodiment of a curtain airbag 100incorporating teachings of the present invention. Airbag 100 includes afill chamber 102 and a safety cushion 104 with a rear portion 106 thatdeploys toward the rear of passenger compartment 12 of vehicle 14 ofFIG. 1. Safety cushion 104 is subdivided into cushion chambers 108 a-108f by the internal attachment zones between the panels of airbag 100,which are not labeled in FIG. 4C.

To enhance the post-deployment lateral stability of safety cushion 104,airbag 100 also includes an inflatable structural member 110. Structuralmember 110 communicates with rear portion 106 of safety cushion 104 atan upper edge 112 thereof by way of an auxiliary passageway 114 that hasan entrance 116 at cushion chamber 108 f and an outlet 118 at structuralmember 110. The portion Gf of pressurized gas G entering cushion chamber108 f at rear portion 106 of safety cushion 104 is identified, as is thefraction G₁₁₀ of portion Gf that eventually enters structural member 110by way of auxiliary passageway 114. A fold F₁₁₀ is also shown at upperedge 112 of rear portion 106 of safety cushion 104. When airbag 100 isto be installed in a vehicle, structural member 110 in a deflatedcondition is rotated downward from the plane of FIG. 4 about fold F₁₁₀until structural member 110 rests against rear portion 106 of safetycushion 104, which is also in a deflated condition.

FIG. 5 is an elevation view of a fourth embodiment of a curtain airbag130 incorporating teachings of the present invention with occupants 24and 26 of vehicle 14 of FIG. 1 in the foreground. Airbag 130 isfabricated from a pair of coextensive, congruent, flexible,gas-impermeable fabric panels. These include an inboard panel 132visible in FIG. 5, which comes to be disposed facing occupants 24 and 26when airbag 130 is deployed, and an outboard panel that is obscured inFIG. 5 by inboard panel 132. The outboard panel of airbag 130 will,therefore, be introduced in relation to a subsequent figure. The panelsof airbag 130 are disposed in alignment atop one another and securedwith adhesive and/or stitching at a continuous exterior attachment zoneat the common periphery P of both. Enclosed thereby between the panelsis an interior space in which airbag 130 captures pressurized gas andinflates. Such pressurized gas G is shown diagrammatically in FIG. 5 asan arrow in the process of being delivered into airbag 130 through anopen end 133 thereof. Open end 133 of airbag 130 is the sole portion ofcommon periphery P of the panels of airbag 130 that, being free of anyexterior attachment zone, are not secured to each other.

The fabric panels of airbag 130 are also secured to each other atselected interior attachment zones within periphery P. The interiorattachment zones of airbag 130 direct the flow of pressurized gas Gthroughout airbag 130 appropriately and determine the shape into whichairbag 130 will ultimately inflate. Of the various interior attachmentzones of airbag 130, only elongated plenum boundaries 134 a-134 f areshown in FIG. 5.

Plenum boundaries 134 a-134 f are positioned in an end-to-end alignmentthat mirrors the shape of the top 135 of airbag 130. At the end of eachof plenum boundaries 134 a-134 f remote from open end 133 of airbag 130is a corresponding gas flow gap 136 a-136 f. Thus, for example, gas flowgap 136 a is located between plenum boundaries 134 a and 134 b, whilegas flow gap 136 f, the furthest gas flow gap from open end 133 ofairbag 130, is between plenum boundary 134 f and periphery P of thepanels of airbag 130. Pressurized gas G entering airbag 130 is initiallydirected away from open end 133, between plenum boundaries 134 a-134 fand top 135 of airbag 130. Fractional portions Ga-Gf of pressurized gasG bleed through each of gas flow gaps 136 a-136 f, respectively,entering and inflating the portion of airbag 130 between plenumboundaries 134 a-134 f and the bottom 137 of airbag 130. Thus, portionGa of pressurized gas G enters the portion of airbag 130 between plenumboundaries 134 a-134 f and bottom 137 by way of gas flow gap 136 a,while portion Gf enters through gas flow gap 136 f.

Plenum boundaries 134 a-134 f accordingly separate airbag 130 into anelongated, tubular fill chamber 138 that is located between plenumboundaries 134 a-134 f and top 135 of airbag 130, and an inflatablepassenger safety cushion 140 that is located between plenum boundaries134 a-134 f and bottom 137 of airbag 130. Safety cushion 140 has a topedge 142 identified in FIG. 5 by a dashed line just below plenumboundaries 134 a-134 f. Fill chamber 138 is secured to top edge 142 ofsafety cushion 140 and accordingly supports safety cushion 140 interiorof vehicle 14 for deployment into passenger compartment 12 in the mannerillustrated in FIG. 1. Fill chamber 138 communicates pneumatically withsafety cushion 140 at top edge 142 thereof by way of gas flow gaps 136a-136 f. Thus, fill chamber 138 directs pressurized gas G into safetycushion 140 in portions Ga-Gf, which vary in quantity relative to eachother according to the specific configuration of each of gas flow gaps136 a-136 f.

In the deployed condition, airbag 130 is stably secured at the top 135thereof to the occupant enclosure that surrounds vehicle compartment 12.The bottom 137 of airbag 130 is by contrast relatively less restrained,particularly in a lateral outboard-inboard direction. Contributing tothis lateral instability is the separation of airbag 130 into fillchamber 138 and safety cushion 140 by plenum boundaries 134 a-134 f. Atplenum boundaries 134 a-134 f, the panels of airbag 130 are secureddirectly to each other, and the panels of airbag 130 remain so secured,even when fill chamber 138 and safety cushion 140 are inflated. Thus,once airbag 130 has been deployed, and fill chamber 138 and safetycushion 140 are inflated, the narrowing of the panels of airbag 130 toform plenum boundaries 134 a-134 f causes the portion of airbag 130traversed by plenum boundaries 134 a-134 f to act like a hinge betweenfill chamber 138 and safety cushion 140. Safety cushion 140 has atendency to pivot relative to fill chamber 138 about plenum boundaries134 a-134 f.

Safety cushion 140 has a rear portion 144 that deploys toward the rearof passenger compartment 12 in FIG. 1 and a forward portion 146 remotetherefrom that correspondingly deploys toward the front of passengercompartment 12.

FIG. 6 is a cross section of rear portion 144 of airbag 130 taken alongsection line 6-6 in FIG. 5. By way of perspective, that view of airbag130 is superimposed against profiles in phantom of exterior 22 ofvehicle 14 of FIG. 1 and of occupant enclosure 48 for passengercompartment 12. A rear view of back seat occupant 26 is also included.

Airbag 130 has deployed downwardly from the ceiling trim of vehicle 14into passenger compartment 12 between occupant 26 and the portion ofoccupant enclosure 48 at rear side window 20. Fill chamber 138 supportssafety cushion 140 from top edge 142 thereof and communicates thereintothrough gas flow gap 136 e. The panels of airbag 130, inboard panel 132and outboard panel 150 not previously visible in FIG. 5, are securedalong an exterior attachment zone at their common periphery P, therebyenclosing the interior space in which airbag 130 captures and inflateswith pressurized gas G.

To enhance the post-deployment lateral stability of safety cushion 140,airbag 130 also includes an inflatable structural member 152 that ismechanically connected to safety cushion 140 by way of fill chamber 138.Structural member 152 is disposable upon installation in vehicle 14 fordeployment into passenger compartment 12 along a portion of top edge 142of safety cushion 140 corresponding to the seated position of occupant26 in passenger compartment 12 between the deployed safety cushion 140and occupant enclosure 48 using pressurized gas from fill chamber 138.As thusly deployed, structural member 152 serves to limit pivoting ofsafety cushion 140 at top edge 142 thereof, in the vicinity of plenumboundaries 134 a-134 f. This thwarts associated outboard displacement ofsafety cushion 140, reducing the risk of injury to occupant 26.

Structural member 152 is fabricated from the same inboard panel 132 andoutboard panel 150 as are used in forming fill chamber 138 and safetycushion 140 and in the same manner, by securement along an exteriorattachment zone at their common periphery P. An auxiliary passageway154, also fabricated from inboard panel 132 and outboard panel 150,communicates between fill chamber 138 and structural member 152.Auxiliary passageway 154 has an entrance 156 at fill chamber 138 thatreceives pressurized gas therefrom and an outlet 158 at structuralmember 152 at which that pressurized air enters and inflates structuralmember 152. Entrance 156 to auxiliary passageway 154 is located at theupper edge 159 of fill chamber 138, and accordingly structural member152 communicates with fill chamber 138 at upper edge 159 thereof.

When airbag 130 is installed in vehicle 14, structural member 152 in adeflated condition is folded back upon and optionally secured to safetycushion 140 in a deflated condition. As a result, a fold arises betweenstructural member 152 and fill chamber 138. This fold traversesauxiliary passageway 154, and entrance 156 to auxiliary passageway 154is oriented in a direction opposite from the direction of outlet 158 ofauxiliary passageway 154. This tortuous gas flow pathway between fillchamber 138 and structural member 152 delays the full deployment ofstructural member 152 relative to the completion of the full deploymentof safety cushion 140.

FIG. 7 is an elevation view of airbag 130 of FIGS. 5 and 6 in anunfolded condition with inboard panel 132 removed to depict on outboardpanel 150 the attachment zones at which the panels of airbag 130 becomemutually secured. These attachment zones include, not only plenumboundaries 134 a-134 f already introduced in FIG. 5, but an exteriorattachment zone 160 at periphery P and internal attachment ribs 162 thatsubdivide safety cushion 140 into cushion chambers 164 a-164 f.

To enhance protection for a specific single occupant, such as occupant26, the length L₁₅₂ of structural member 152 may be made less than thelength L₁₄₀ of safety cushion 140. Portion G₁₅₂ of pressurized gas Genters structural member 152 by way of auxiliary passageway 154. A foldF₁₅₂ is shown at the upper edge 159 of fill chamber 138. When airbag 130is to be installed in a vehicle, structural member 152 in a deflatedcondition is rotated downward from the plane of FIG. 7 about fold F₁₅₂until structural member 152 rests against top edge 142 of safety cushion140, which is also then in a deflated condition.

The present invention may be embodied in other specific forms withoutdeparting from its structures, methods, or other essentialcharacteristics as broadly described herein and claimed hereinafter. Thedescribed embodiments are to be considered in all respects only asillustrative, and not restrictive. The scope of the invention is,therefore, indicated by the appended claims, rather than by theforegoing description. All changes that come within the meaning andrange of equivalency of the claims are to be embraced within theirscope.

1. A post-deployment position-stabilized curtain airbag for installationin a vehicle to protect an occupant in case of side impact or rollover,the airbag comprising: (a) an inflatable passenger safety cushionsupportable at a top edge thereof interior of the vehicle for deploymentinto the passenger compartment of the vehicle between the occupant andthe occupant enclosure; (b) a fill chamber secured to the top edge ofthe safety cushion in fluid communication therewith, the fill chamberdirecting pressurized gas from an inflator into the safety cushion toeffect deployment thereof; and (c) an inflatable structural memberhaving closed peripheral sides and being mechanically connected to thesafety cushion by an auxiliary passageway disposed between thestructural member and the safety cushion such that the closed peripheralsides are separate from the safety cushion, the structural member beingdisposable upon installation in the vehicle for deployment into thepassenger compartment between the deployed safety cushion and theoccupant enclosure using pressurized gas directed through the fillchamber and the auxiliary passageway, the deployed structural memberserving to limit outboard displacement of the deployed safety cushion,wherein the structural member deploys along the top edge of the safetycushion, and the deployed structural member serves to limit pivoting ofthe deployed safety cushion at the top edge thereof relative to the fillchamber.
 2. A post-deployment position-stabilized curtain airbag forinstallation in a vehicle to protect an occupant in case of side impactor rollover, the airbag comprising: (a) an inflatable passenger safetycushion supportable at a top edge thereof interior of the vehicle fordeployment into the passenger compartment of the vehicle between theoccupant and the occupant enclosure, the safety cushion having a rearportion deploying toward the rear of the passenger compartment and aforward portion remote therefrom; (b) a fill chamber secured to the topedge of the safety cushion in fluid communication therewith, the fillchamber directing pressurized gas from an inflator into the safetycushion to effect deployment thereof; (c) an inflatable structuralmember mechanically connected to the rear portion of the safety cushion,the structural member being disposable upon installation in the vehiclefor deployment into the passenger compartment between the deployedsafety cushion and the occupant enclosure using pressurized gas directedfrom the fill chamber through the safety cushion, the deployedstructural member serving to limit outboard displacement of the rearportion of the deployed safety cushion, wherein the full deployment ofthe structural member is completed after the completion of the fulldeployment of the safety cushion; and (d) an auxiliary passagewaycommunicating between the rear portion of the safety cushion and thestructural member, and pressurized gas from the safety cushion entersthe structural member through the auxiliary passageway, wherein theauxiliary passageway communicates with the safety cushion at a loweredge of the rear portion of the safety cushion.
 3. A curtain airbag asrecited in claim 2, wherein the structural member is folded against thesafety cushion along a transverse axis of the auxiliary passageway priorto deployment.
 4. A post-deployment position-stabilized curtain airbagfor installation in a vehicle to protect an occupant in case of sideimpact or rollover, the airbag comprising: (a) an inflatable passengersafety cushion supportable at a top edge thereof interior of the vehiclefor deployment into the passenger compartment of the vehicle between theoccupant and the occupant enclosure; (b) a fill chamber secured to andcommunicating with the safety cushion at the top edge thereof, the fillchamber directing pressurized gas from an inflator into the safetycushion to effect the deployment thereof; and (c) an inflatablestructural member having closed peripheral sides and being mechanicallyconnected to the safety cushion by an auxiliary passageway disposedbetween the structural member and the safety cushion such that theclosed peripheral sides are separate from the safety cushion, thestructural member being disposable upon installation in the vehicle fordeployment into the passenger compartment along the top edge of thesafety cushion between the deployed safety cushion and the occupantenclosure using pressurized gas directed through the fill chamber andthe auxiliary passageway, the deployed structural member serving tolimit pivoting of the deployed safety cushion at the top edge thereofrelative to the fill chamber.
 5. A curtain airbag as recited in claim 4,wherein pressurized gas enters the structural member directly from thefill chamber.
 6. A curtain airbag as recited in claim 4, wherein thestructural member is folded against the safety cushion along atransverse axis of the auxiliary passageway prior to deployment.
 7. Acurtain airbag as recited in claim 4, wherein the length of thestructural member is less than the length of the safety cushion.
 8. Acurtain airbag as recited in claim 7, wherein the structural memberdeploys along a portion of the top edge of the safety cushioncorresponding to the seated position of the occupant in the passengercompartment.